Question

Which would you expect to be more easily oxidized, \(\mathrm{Ti}^{2+}\) or \(\mathrm{Ni}^{2+} ?\)

Short answer

Ti\(^{2+}\) would be more easily oxidized than Ni\(^{2+}\) since it has a lower standard reduction potential of -1.63 V compared to Ni\(^{2+}\) which has a value of -0.26 V. The lower reduction potential indicates that Ti\(^{2+}\) has a greater tendency to lose electrons and form a more positive oxidation state.

Step-by-step solution

Understanding standard reduction potentials

First, it's essential to understand that standard reduction potentials indicate the tendency of a chemical species to gain electrons and be reduced. A higher positive standard reduction potential means that a species is more likely to be reduced, while a lower (or negative) standard reduction potential means that a species is less likely to be reduced.

Locate standard reduction potentials for the given species

Consult a standard reduction potential table and locate the information for \(\mathrm{Ti}^{2+}\) and \(\mathrm{Ni}^{2+}\). In this case, we find that: - For \(\mathrm{Ti}^{2+}\): Ti \( \rightleftharpoons \) Ti\(^\mathrm{II}\) + 2e\(^{-}\); E° = -1.63 V - For \(\mathrm{Ni}^{2+}\): Ni \( \rightleftharpoons \) Ni\(^\mathrm{II}\) + 2e\(^{-}\); E° = -0.26 V

Compare standard reduction potentials

Comparing the standard reduction potentials for these species, we can see that Ti\(^\mathrm{II}\) has a more negative standard reduction potential (-1.63 V) compared to Ni\(^\mathrm{II}\) (-0.26 V).

Determine which ion is more easily oxidized

Recall that the species with the lower standard reduction potential is more likely to be oxidized. In this case, the \(\mathrm{Ti}^{2+}\) ion has a lower standard reduction potential compared to \(\mathrm{Ni}^{2+}\), so Ti\(^\mathrm{II}\) will be more easily oxidized.